Conventionally, there are available disc players in which information signals are read from a disc-shaped recording medium for reproduction. Such disc players include so-called vertical or upright types in which a disc-shaped recording medium is played back with the main side of the recording medium being chucked generally parallel to the vertical direction.
One typical example of the vertical-type disc players of the above type will be described with reference to FIG. 1. To prevent a disc-shaped recording medium 101 (will be referred to as “disc” hereunder) going to be set on a disc table 103 from falling off a truncated cone-shaped centering projection 104 before it is pinched between the disc table 103 and a clamper 102, there is provided in the disc player a receiving member 105 which receives therein a part of the outer-circumferential portion of the disc 101 as shown in FIG. 1. In such a disc player, after the disc 101 is pinched or securely held between the clamper 102 and disc table 103, the receiving member 105 is moved to a predetermined position away from the disc-shape recording medium 101, the latter is rotated as the disc table 103 is rotated, and thus information signals are read from the disc 101.
In the disc player incorporating the receiving member 105 as shown in FIG. 1, however, when the disc 101 is received in the receiving member 105 and when the chucking is complete and thus the disc 101 has not to be received any longer, the receiving member 105 has to be moved away from the disc 101. To this end, in the disc player shown in FIG. 1, there should be provided a mechanism to move the receiving member 105 away from the disc 101, which will disadvantageously result in a complicated construction of the disc player and increased costs of manufacture because the moving mechanism and receiving member 105 are required.
All the disc-shaped recording media are not identical in diameter to one another. That is, for playback of all such disc-shaped recording media of different diameters by one disc player, a position to which the receiving member 105 is to be moved should be set for each of the disc-shaped recording media of different diameters, which will further complicate the construction of the moving mechanism.
Also, another typical example of the vertical-type disc players will be described with reference to FIG. 2. In the disc player, there is provided along the outer circumference of a centering projection 112 of a disc table 111 metal balls 114 which are movable radially of the centering projection 112 by a plurality of spring members 113. When setting the disc 101 in the disc player, the inner circumference of the disc 101 pushes the metal balls 114 which will thus be moved the center of the centering projection 112. When the inner circumferential edge of the disc 101 has been moved over the metal balls 114, the elasticity of the spring members 113 returns the metal balls 114 to their initial positions for engagement of the metal balls 114 on the inner circumferential edge of the disc 101, thereby setting the disc 101 onto the disc table 111.
In the disc player using the metal balls 114 as shown in FIG. 2, however, for setting the disc 101 onto the disc table 111, the disc 101 has to be moved toward the center axis of the disc table 111 in order to move the metal balls 114 toward the center of the centering projection 112, which will apply, when the disc 101 is going to be set on the disc table 114, a pressure to the disc 101 which will possibly be damaged by the pressure.